1. Field of the Invention
The present invention relates to an information storage medium having grooves that are concentrically or spirally formed. The present invention also relates to an information recording apparatus for recording information on such a storage medium. The present invention also relates to an information playback apparatus for playing back information from such an information storage medium.
2. Description of the Related Art
Research and development of large-capacity information storage media such as optical disks are recently advancing. An information storage medium has, e.g., tracks that are concentrically or spirally formed. Japanese Patent Nos. 2844638 and 2840631 describe techniques for recording information by displacing a track.
Control information recording by track displacement described in the above prior arts suffers from the problem of low recording density.